Overhead visual shutter device

ABSTRACT

An overhead projector shutter assembly having a frame defining a window and a number of slides movably mounted in the frame to mask the window, the slides being selectively and relatively movable to mask and unmask selected portions of the window or the entire window to project selected portions of the total transparency onto a screen in sequence. The slides are overlapped with each other and with the frame along adjacent edges to completely exclude unwanted light and to promote smoothness of operation on guides which assure accuracy of alignment between the slides and the register pins which locate the transparency.

o i United States Patent [151 3,661,449 Wright 1 May 9, 1972 541 OVERHEAD VISUAL SHUTTER DEVICE 3,412,480 I l/1968 Connell .Q .353/27 x 72 inventor: John 5. Wright, 6115 North Lake Drive 2'33??? 313:8 gx

Court, Milwaukee Wis" 53217 [22] Filed: May 19, 1969 Primary Examiner-William D. Martin,Jr. [21] A l N 825 902 Att0rney-Wheeler, House & Wheeler [57] ABSTRACT [52] 3 0 6 An overhead projector shutter assembly having a frame defin- G03; 21/14 ing a window and a number of slides movably mounted in the [51] Int. Cl. I21 122 frame to mask the window, the slides being selectively and [58] Fleld of scam "55 4 95/36 relatively movable to mask and unmask selected portions of the window or the entire window to project selected portions of the total transparency onto a screen in sequence. The slides [56] References cued are overlapped with each other and with the frame along ad- UNITED STATES PATENTS jacent edges to completely ea clude unwanted light and to promote smoothness of operation on guides which assure ac- 28,739 6/1860 Corbett ..95/37 curacy f alignment between the slides and the register pins 9 7.56 1910 g g which locate the transparency. 3,264,767 8/1966 0 man 3,280,694 10/1966 Buechner..... ..355/54 10 Claims, 8 Drawing Figures PATENTEDMAY 9 1912 SHEET 1 BF 2 mvzwroz JOHN 5- WE/HT 1 ovsnassn VISUAL SHUTTERDEVICE BACKGROUND OF THEINVENTION In my copending applicationS er. No. 748,255, now U.S. Pat. No. 3,524,703, a transparency storage anddisplay book is shown having a pack of transparencies hingedly connected. to the free edge of the book cover for pivotalv movement onto a stage for viewing and into the book-for storage The transparencies are presented in a predeterminedorder to show a series of images by placing one transparency at atime onto the stage. If an image in a series is to. be reshownthe particular transparency containing the image must'befound in the pack and replaced on the stage.

If a selected portion of a transparency is to be, shown, a separate opaque mask is generally -use d to block thelight and prevent the projection of the other portions of the transparency. Any time a separate mask is used a certain amount of distraction occurs which disrupts the presentation of the trans parency. l

SUMMARY OF THE TNVENTION The shutter assembly disclosed herein provides for the sequential showing of a seriesof images using a single transparency. One or more of the transparency sections canbe projected at one time and the series of images can be shown or remasked in any desired sequence or order. The shutter assembly includes a frame defining a window and a number. of opaque shutters or slides mounted in the frame. Theshutters slide into or out of the frame to open or, unmask portions of screen. This. is accomplished by overlapping; the adjacent edges and ends of the shutters with each other and'withthe frame.

Other objects and advantages will become. apparent from the following description when read in connection with the accompanyingdrawings in which:

FIG. 1 is a perspective view of. an overhead projector with the'shutter assembly positioned on the primary stage- FIG. -2 is a perspective view of the shutter assembly.

FIG. 3 is a view taken on line 3-3 of FIG. 2 showingthe overlap at the end of the shutters.

FIG. 4 is a view taken on line 4-4 of FIG. 2showing theshutter guide arrangement and the overlap arrangement of the edges of the shutters.

FIG. 5 is a perspectiveview of a modified arrangement of the shutter assembly mounted on the projector.

FIG. 6 is a perspective view of another arrangement ofthe shutter assembly mounted on the projector. I

FIG. 7 is an enlarged view of the overlapped ends of the shutters.

FIG. 8 is an enlarged view of the overlapped edges of the shutters.

DESCRIPTION OF THE INYE NTION Although the disclosure hereof is detailed and exact to enable those skilled inthe art to practicethe invention, the physical embodiments herein disclosed merely exemplify the invention, which may be embodied in other specific. structure.

The. shutter assembly 10 of this invention is ordinarily (but not necessarily) used in combination with an overhead projector 12 of the type shown in FIG. 1 which includes a primary stage 14 and a lens housing 16 supported by a bracket 18 on an arm 20. A light is directed from within the primary stage 14 upwardly through the lens housing 16 for projection onto a 10 for projection of the images onthe transparency 22 onto the screen. 1

In accordance with the invention, means are. provided for selectively projecting: onto the screenportionsof the transparency 22 to present the images of the transparency in a predetermined order or sequence. Such means comprises the shutter assembly 10 which includes means for defining a window 26: in the form of a-frame 24 and means for selectively masking all or. portions of thewindow 26 by using a number of shutters 28. The'frame 24 includesan upper frame part 30 having side; members 32 and' end members34' and a bottom frame part-36 having sidemembers 38andend'members 40. Theupper frame part30 is secured to the bottom frame part 36' todefine the window-'26. The frame 24 is arranged on the projector 12 so that all of the light passes through the window 26. Theshutters28- are moved into and'out oflight obstructing positionszon the frame 26 tomaskor unmaskportions of the window 26 in apredetermined sequence to control projection of selected-imagesof the transparency onto the screen.

In thisregard, means are provided in the frame 24 for masking the window 26 in the form of a number ofthe opaque shutters or slides 28 each of which has an inside edge 42, an outside edge' 44, an inner end 46 and an outer end 48. The slides 28are mounted for sliding movement between the frame parts 30 and 36 to unmask portions of thewindow 26 in sequence or to open the entire window 26. Each slide 28 is actuated by meansofa flange 50 provided on its outer end 48. A recess 52 can-be provided in the side members 32 of the upper frame part 30. to receive each of the flanges 50. The upper portion of each flange 50 projects above the side members 32. The outward movement of each of the slides 28 is limitedby means of azstop or ridge 54 providedonthe inner end of each of the slides 28in a position-to engage a sidemember 38iofthe bottom frame part 36., The slides 28- can be actuated in any sequence. or as'many at onetime as desired. The shutters can be. actuated simultaneously; to unmask' more than one. portion of the transparency. atone time. v

The slide sx28. are prevented from'wobblingin the shutter assembly 10.-bymeans of a guide in the form ofan offset flange orledge-56 provided on-the outer edge 44'ofeach of'the slides 28- and a groove 58. provided in the end members 40 on the bottom frame part 36. The ledges 56, are retained in the grooves 5 8 by'the end'members 34 which overlie the-ledges $6 andare providedwith a notch 60m provide clearancefor the outside edge 44 of 'the slides28. Thewidth of the groove 58 is substantially equal to the width of the ledge'56toassure jection or flange 62.provided'acro'ss the end 46 of one of the slides 28 and a beveled edge "64 providedacross the end 46 of the opposite slide 28. On complete closure of the slides 28, the ledges62 will matingly engage the beveled edge 64 to prevent theprojection oflight through the line of contact between the ends 44 of the slides 28. The lap joint at the inside edges 42 of adjacent slides28 is providedby means of an upper flange 66 provided on theinside edge 42 of one of the slides-28and a lower flange 68 provided on the inside edge 42 ofthe adjacent slide 28. The flange 66 will lap the flange whenever any portion of the inside edges 42 of the slides 28 are adjacent each other. Not only do these joints exclude undesirable leakage of light but they also provide guidance for very smooth movement of the slides.

The shutter assembly 10 can be adapted for useas an auxiliary stage as shown in my copending application Ser. No. 748,255 by providing means for supporting a transparency on the frame 24. Such means can be in the form of a transparent sheet of plastic or glass 70 retained by tabs 72 in a groove 74 provided in the side members 32 and end members 34 of the upper frame part 30 as shown in FIGS. 2, 3 and 4. Means can also be provided on one of the end members 32 for supporting a transparency storage and display book as shown in copending application Ser. No. 748,255 in the form of side wall extensions 76 having channel shaped grooves 78. In this type of a book, a pack of transparencies are hingedly connected to the free edge of the cover for successive pivotal movement of the transparencies onto the transparent glass 70. The auxiliary stage is retained in a fixed position on the primary stage by providing an adhesive tape 75 at each of the corners of the frame 24.

Exposure of an identical portion of each of the transparencies 22 is provided by means of register pins 80 located in a predetermined relation to the slides or shutters28. The pins 80 may be provided on the primary stage 14 or on one of the end members 34 of the upper frame part 30. Openings are provided in each of the transparencies 22 as shown in my copending application Ser. No. 748,255 which are engageable with the pins 80 to align the transparencies 22 in the same position on the glass 70.

The shutter assembly 10 can also be attached to the projector 12 as an independent unit as shown in FIGS. 5 and 6. In FIG. 5 the shutter assembly is shown as an attachment secured to the upright arm 20 by means of a bracket 82. The shutter assembly 10 is essentially the same as described above having shutters 28 mounted for sliding movement in a frame 24. The frame 24 is mounted in a transverse relation to the light path in the projector 12. In FIG. 6 the shutter assembly 10 is shown attached to the front of the lens housing 16 by means of brackets 84. In each of the arrangements shown in FIGS. 5 and 6, accuracy of alignment of the transparency 22 with respect to the shutter assembly 10 is achieved by providing the registration pins 80 on the surface of the primary stage 14. It is also possible to incorporate the shutter assembly 10 as an integral part of the primary stage '14. In all of these arrangements the size of the window 26 will vary depending on the cross directional size of the light path.

What is claimed is:

l. A stage for supporting transparencies in an overhead projector system, said stage comprising a frame with inner and outer margins and a fullsize projection opening, a transparent sheet mounted on said frame for the support of transparencies to be projected, register pins on the frame for the precise location on said sheet of successive transparencies for projection, and a shutter having means mounting it on said frame for movement beneath the transparent sheet on which the transparencies are supported.

2. A stage in accordance with claim 1 in which a plurality of shutters are disposed beneath the transparent sheet for relative movement between positions to open and to mask specifically identified portions of the sheet and the transparency thereon, margins of the respective shutters having edge portions lapping each other and respective portions of the frame.

3. A stage in accordance with claim 2 in which the frame comprises side members with slots through which respective shutters are movable outwardly from completely effective mask positions to positions in which areas of said transparent sheet controlled by the respective shutters are substantially fully exposed.

4. A stage according to claim 3 in which the shutters and frame have mutually engageable limiting means for restraining outward shutter movement beyond the last mentioned positions.

5. For use with an overhead projector, a shutter assembly having a frame provided with inner and outer margins and a full size projection opening, a set of masks movable between first positions for completely closing said opening and second positions for completely exposing said opening and selected positions for closing only selected portions of said opening, and first guide means on the inside margin of the frame and additional guide means on the masks for guiding said masks for movement between said positions, w ereby sard masks may pass to their respective second positions, and means for limiting the movement of said masks to preclude movement from their said first positions to points materially beyond said second position.

6. A shutter assembly according to claim 5 in which said masks have handle flanges exposed at the outer margins of said frame.

7. A shutter assembly according to claim 6 in which the means for limiting mask movement comprises flanges engageable with the inner margins of the frame.

8. A shutter assembly according to claim 5 in which the frame comprises upper and lower elements spaced to provide slots through which said masks are movable.

9. A shutter assembly according to claim 8 in which the upper elements have exterior recesses and the masks have handle flanges seated therein in the said first positions of the masks.

10. A shutter assembly according to claim 5 in which the additional guide means comprises lapping marginal portions of the respective masks which are in engagement. 

1. A stage for supporting transparencies in an overhead projector system, said stage comprising a frame with inner and outer margins and a fullsize projection opening, a transparent sheet mounted on said frame for the support of transparencies to be projected, register pins on the frame for the precise location on said sheet Of successive transparencies for projection, and a shutter having means mounting it on said frame for movement beneath the transparent sheet on which the transparencies are supported.
 2. A stage in accordance with claim 1 in which a plurality of shutters are disposed beneath the transparent sheet for relative movement between positions to open and to mask specifically identified portions of the sheet and the transparency thereon, margins of the respective shutters having edge portions lapping each other and respective portions of the frame.
 3. A stage in accordance with claim 2 in which the frame comprises side members with slots through which respective shutters are movable outwardly from completely effective mask positions to positions in which areas of said transparent sheet controlled by the respective shutters are substantially fully exposed.
 4. A stage according to claim 3 in which the shutters and frame have mutually engageable limiting means for restraining outward shutter movement beyond the last mentioned positions.
 5. For use with an overhead projector, a shutter assembly having a frame provided with inner and outer margins and a full size projection opening, a set of masks movable between first positions for completely closing said opening and second positions for completely exposing said opening and selected positions for closing only selected portions of said opening, and first guide means on the inside margin of the frame and additional guide means on the masks for guiding said masks for movement between said positions, whereby said masks may pass to their respective second positions, and means for limiting the movement of said masks to preclude movement from their said first positions to points materially beyond said second position.
 6. A shutter assembly according to claim 5 in which said masks have handle flanges exposed at the outer margins of said frame.
 7. A shutter assembly according to claim 6 in which the means for limiting mask movement comprises flanges engageable with the inner margins of the frame.
 8. A shutter assembly according to claim 5 in which the frame comprises upper and lower elements spaced to provide slots through which said masks are movable.
 9. A shutter assembly according to claim 8 in which the upper elements have exterior recesses and the masks have handle flanges seated therein in the said first positions of the masks.
 10. A shutter assembly according to claim 5 in which the additional guide means comprises lapping marginal portions of the respective masks which are in engagement. 